Brake mechanism for well machinery



Sept. 1, 1936; A. J. NEFF BRAKE MECHANISM FOR WELL MACHINERY Filed Jan. 25, 1936 4 Sheets-Sheet}.

Sept. 1, 1936. A. J. NEFF BRAKE MECHANISM FdR WELL MACHINERY Filed Jan. 25, 1936 4 Sheets-Sheet 2 l 1935- A. J. N EFF MECHANISM FOR WELLMACHINERY BRAKE Filed iJan. 25, 1936 1 sheets-sh et 3 Sept. 1, 1936. A. J. NEFF MECHANISM FOR WELL MACHINERY BRAKE 4 Sheets-Sheet 4 Filed Jan 25, 1936 Patented Sept. 1, 1936 UNIT-ED STATES PATENT OFFICE BRAKE MECHANISM FOR WELL MACHINERY 9 Claims.

This invention relates to means for controlling the brake of well machinery such as draw works drilling machines.

An object is to provide, a brake of simple construction which is adjustable to produce the desired braking effect for every condition of drilling and forraising and lowering the drill pipe or setting the casing.

Another object is to enable the operator to make adjustments quickly to meet any conditions and at the same'time relievehim from the necessity of weighting or tying, the brake lever to hold the brake properly while the machine is in operation,

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claims, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

In the accompanying drawings the preferred form of the invention has been shown.

In said drawings Figure 1 isja front elevation of a portion of a well machine having the present improvements, portions being broken away.

Figure 2 is an end view thereof partly in section and partly in elevation.

Figure 3 is a plan view with parts broken away.

Figure 4 is a side elevation of the brake applying and locking mechanism,-shown in released position by full lines and in applied, locked position by broken lines, thebrake lever being broken away.

Figure 5 is a transverse section through one of the bearings of the brake mechanism and showing said mechanism in elevation.

Figure 6 is a side elevation of the brake adj-usting mechanism. a

Figure '7 is a front elevation thereof.

Referring to the figures by characters of reference, I designates'the frame of the well machinery on which are mounted the usual brake drums 2 the periphery of each of which is engaged by a brake b'and'e. Lugs 4 can be connected to the bands at one end for engagement by adjustable connecting rods 5 pivoted to the ends of a centrally fulcrumed equalizing lever B.

Fixedly secured to the frame I are spaced bearings 1 in each of which is located a cylindrical bushing 8 having a radial arm 9. An eccentric bore II] is provided in each bushing and these bores receive a shaft I I.

Mounted on shaft II so as to rotate therewith are arms I2 and I3 arranged in pairs, each pair being coupled to one of the bands 3 at that end remote from the lug 4. Thus when the shaft II is rotated in one direction the arms I2 and I3 will pull on the bands 3 so as to tighten them about brake drums 2, the pressure of the two bands being equalized by lever I5.

One of the arms I2 has an extension I4 joined by a link I5 to an arm I 6 extending radially from a brake operating shaft H. A hand lever I8 is utilized for rocking shaft I1 and during such movement the arm I6 and link I5 act as a toggle for transmitting motion to extension I4, arms I2 and shaft l I, thereby to apply or release the brake.

The axial center of the point of connection between arm I6 and link I5 has been indicated at a and the axial center of the point of connection between link I5 and extension I4 has been indicated at b. Theaxial center of shaft I1 is shown at c.

When the brake is to be applied, the lever I8 is moved from full-line to broken line position in Figure 4. This causes the arm I6 to press through link I5 against extension I4, causing the shaft II to rotate in one direction and apply the brake bands to the drums. When the point of extreme application is reached the centers 0, a and b have assumed the positions indicated at c, a. and b where they are either on a dead center or slightly past the dead center, being limited by a suitably disposed stop I9 engaged by lever I8 or some other part of the mechanism. Thus the brake will be held in applied position and it is not necessary to weight or tie down the lever I8 in order to relieve the operator.

Should it be desired to reduce or increase the slack in bands 3 so that their maximum pressure upon the drums will be either increased or reduced to meet the working requirements, the two bushings 8 can be simultaneously rocked to advance shaft I I toward or retract it from the brake drums. This operation is effected by means of an adjusting shaft having radial arms 2| connected by links 22 to the arms 9 on the bushings. An adjusting lever 23 is secured. to shaft 20 and by means thereof the shaft can, be rocked to adjust the bushings annularly and effect the desired advance or retraction'of the shaft II. Any suitable means such as a dog 24 and a toothed segment 25, can be employed for holding the lever 23 and associated parts in any positions to which they may be adjusted.

means operating independently It will be apparent from the foregoing that the frictional engagement of the brake bands with the drums can be quickly and easily increased at the will of the operator at any time simply by shifting lever 23 and no matter to what position this lever may be moved, the toggle formed by arm 5 and link l5 will always be brought to or slightly past dead center position when the lever I8 is given its maximum movement in onedirec:

tion. Consequentlythe brake will be held or locked in full applied position following any ad justment thereof. By providing a brake which can be quickl and easily adjusted, and which will beheld when applied as described, it will meet any requirements such as lowering or lifting a drill pipe, setting a well casing, etc.

What is claimed is: a

1. In a brake mechanism a brake drum, a band, a rocker shaft, means operated by said shaft for shifting said band relative to the drum, positively controlled adjusting means operable by the user for changing the position of the shaft by advancing or retractingthe shaft bodily relative to the drum to increase or reduce the slack in the band, and means for rocking the shaft and looking it in one extreme position independently of said bodily movement of the shaft, thereby to tighten and hold'the band, said shaft advancing of the action of the shaft rocking means.

2. In a brake mechanism a brake drum, a band, a rocker shaft, means operated by said shaft for shifting said band relative to the drum, means for rotating the shaft in one direction to apply the band to the drum and to hold the shaft against retrograde rotation when brought to one extreme position, and positively controlled means operable by the user for changing the position of the shaft by advancing and retracting the shaft bodily relative to the drum and independently of the action of the shaft rotating means, to vary the pressure of the band upon the drum when the shaft is held in said extreme position.

3. In a brake mechanism a brake drum, a band, a rocker shaft, means operated by saidshaft for shifting said band relative to the drum, toggle means shiftable to or past a dead center for adjusting the shaft annularly in one direction to apply the band to the drum and to' hold the shaft;

apply thebandito the drum and to hold' the shaft against retrograde movement when brought to one extreme position',' means for limiting the movement of the toggle means when in holding position, and means for advancing and retracting the shaft relative to the drum to vary the pressure of the band upon the drum while the toggle means is held by its limiting means.

5. In a brake mechanism a brake drum, a band,

a rocker shaft, means operatedby said shaft for the drum while the shaft is held in said extreme position.

6. In a brake mechanism a brake drum, a band,

I a rocker shaft, means operated by said shaft for shifting said band relative to the drum, toggle means shiftable to or past a dead center for adjusting the shaft annularly in one direction to apply the band to the drum and to hold the shaft against retrograde movement when brought to one extreme position, an eccentric bearing for the shaft, means for adjusting the bearing annularly to advance or retract the shaft relative to the drum to vary the pressure of the band upon the drum while the shaft is held in said extreme position, and means for holding the bearing against movement away from adjusted position. 7. A brake mechanism including cooperating rotatable and anchored brake elements, a rocker shaft, means operated by said shaft for shifting the anchored brake element, a toggle for rotating the shaft to shift the anchored brake element, means for actuating the toggle to or past a dead center to hold the shaft and theshifted brake element against retrograde movement, limiting means for the toggle, and means for shifting the shaft toward or from the rotatable brake element without disturbing the relative positions of the toggle, its operating means and the shaft. 8. A brake mechanism including cooperating rotatable and anchored brake elements, a rocker shaft, means operated by said shaft for shifting the anchored brake element, means for rotating the shaft in one direction to apply the anchored brake element to the rotatable brake element and to hold the shaftagainst retrograde movement when brought to one extreme position, and positively controlled means operable by the user for changing the position of the shaft by advancing or retracting the shaft bodily relative to the rotatable element and independently of the action of the shaft rotating means, tovary the braking pressure of the anchored element when the shaft is held in said extreme position.

9. A brake mechanism including cooperating rotatable and anchored brake elements, a rocker shaft, means operated by said shaft for shifting the anchored brake element, means for adjusting the shaft annularly in one direction to apply the anchored brake element to the rotatable brake element and to hold the shaft against retrograde movement when brought to one extreme position, and means for advancing or retracting the shaft relative to the rotatable element to vary the braking pressure of the anchored element when the shaft is held in said extreme position, said means including a rotatable bushing, means for actuating the bushing, and means for holding the bushing against rotation, said bushing having an eccentric bearing for the shaft.

ASA JU'DSON NEFF. 70 

